This invention relates generally to drawer slides, and more particularly to bearing retainer retention devices for drawer slides.
Telescopic slides for file drawers and the like are often desirable for use in cabinets and other rack mounted applications. Such slides permit easy access to the interior of the drawer. The slides maintain the drawer in a horizontal position regardless of how far the drawer is withdrawn from the cabinet. A typical drawer slide has two or three slide members slidably, i.e., rollingly, connected by sets of bearings riding in raceways formed on the slide members. Individual bearings within a set of bearings are often held in relative position to one another by bearing retainers.
One type of drawer slides is a telescopic drawer slide. In a telescopic drawer slide the various slide members comprising the drawer slide are nested within one another and extend in a telescopic manner. Two-element telescopic slides normally include an outer slide member and an inner slide member. For purposes of exposition, the outer slide member is connected to the cabinet or enclosure, although it is recognized that the inner slide member may instead be so connected. When the outer slide member is connected to the cabinet or enclosure, the slide member affixed to the drawer is the inner slide member. A three-element telescopic slide will additionally normally include an intermediate slide member slidably connected to and between the outer and inner slide members.
Each drawer slide member, whether an outer slide member, inner slide member, or intermediate slide member, generally comprises a vertical web with bearing raceways extending horizontally from upper and lower margins of the vertical web. In addition, for a two-element drawer slide, the bearings slidably connecting the outer and inner slide members are often held by a common bearing retainer. For a three-element drawer slide, the vertically innermost set of bearings, the bearings slideably connecting the inner and intermediate slide members, are also often held by a common bearing retainer. These common bearing retainers generally mirror in shape the drawer slide members. Accordingly, the common bearing retainer also has a vertical web, and flanges extending from the upper and lower margins of the vertical web for retaining bearings.
The outer slide member is generally fixedly attached, by screws or other means, to the cabinet and the inner slide member is also fixedly attached to the drawer. Often a mechanism is provided so that the inner slide member can be disconnected from the outer slide member so that the drawer may be entirely removed from the cabinet. This mechanism must also allow the drawer to be reinserted into the cabinet, which requires that the inner slide member be reinserted within the outer slide member. The process of reinserting the inner slide member within the outer slide member is more easily accomplished if the bearing retainer is maintained in a position near the forward end of the outer slide member, which is towards the cabinet opening, so that the bearings held by the bearing retainer may serve as insertion guides for the slide member. In addition, if the bearing retainer is not maintained in such a position then misalignment of the inner slide member with respect to the outer slide member during the reinsertion process may result in inadvertent contact between the inner slide member and the bearing retainer. As the inner slide member tends to be of a significantly greater thickness than the bearing retainer, this contact may well result in damage to the bearing retainer. Accordingly, maintaining the bearing retainer at the forward of the outer slide member when the inner slide member is detached from the outer slide member is desirable.
A common method of attachment of the outer slide member to the cabinet is to provide screw holes in the vertical web of the outer slide member, and to use the screw holes to mount the slide to the cabinet. In a similar fashion the inner slide member may be mounted to the drawer. Such a method of mounting a slide member to a cabinet or drawer is, however, not free of problems. Accessing the screw holes when the slide is not extended is often difficult. Access to the screw holes of the outer slide member is impeded by the inner slide member when the web of the outer slide member is placed against the cabinet. Similarly, access to the screw holes of the inner slide member is impeded by the outer slide member when the web of the inner slide member is placed against the drawer. With the inner slide member extended such difficulty may be alleviated, but the extended slide may be inadvertently damaged or possibly cause injury to persons due to its projecting nature. Extending the inner drawer slide also requires greater work space for attaching the drawer slide due to the extended inner slide member stretching out from confines of the cabinet or enclosure. Furthermore, an extended drawer slide acts as a lever arm. The weight of the extended drawer slide causes the drawer slide to pivot around an attachment point. This pivoting can cause tilting in the drawer slide as it is being attached and thereby result in misaligned mounting of the drawer slide.
Other methods of attachment are also possible, but these other methods also present problems. For example, a flange may be integrally formed on the outer slide member, the flange having screw holes for mounting the flange to the cabinet. Alternatively, a mounting bracket may also be welded to the outer slide member, the mounting bracket also having screw holes for similarly mounting the mounting bracket to the cabinet. Use of the integrally formed flange or of the mounting bracket, however, requires the use of additional material and requires additional manufacturing steps, thereby increasing the cost of the drawer slide. In addition, the flange and the mounting bracket increase the size, or footprint, of the drawer slide, which may also be undesirable.
Moreover, attachment of the drawer slide to the cabinet and the drawer is often performed separately, with the outer and inner slide members only joined after attachment to the cabinet and the drawer, respectively. Accordingly, and as previously stated, the outer and inner members of the drawer slide must also be separable. This separation of the drawer slide allows access to the screw holes of the outer slide member and the screw holes in the inner side member, as well as avoids problems with an extending drawer slide member.
Even if the drawer slide is separated, however, the bearing retainer, holding the ball bearings that slidably connect the slide members, is present. The bearing retainer also blocks access to the screw holes in the vertical web of the outer slide member. Forming apertures in the vertical web of the bearing retainer is one way of providing access to the screw holes. As the vertical web of the bearing retainer is not a load bearing portion of the drawer slide, but instead only serves to maintain the bearings in proper relative position, the access holes may be large.
Even with large access holes, however, the bearing retainer must still be properly positioned with respect to the slide member to allow access to the screw holes. Further, the bearing retainer should be restrained from movement during the mounting procedure as movement of the bearing retainer may result in misalignment of the bearing retainer access holes and the screw holes, even if the apertures in the bearing retainer and slide member are initially aligned. However, some slight amount of play in the restrained bearing retainer is also desirable.